Tortilla production and sales is a large industry, by industry estimates, accounting for over five billion dollars in sales in 2002. The production of flat food products, such as tortillas, like much of the commercial food industry, conventionally requires significant manual labor that is repetitive and boring, and may lead to injuries, such as repetitive motion injuries or injuries related to worker inattention around moving and/or hot equipment. Moreover, the use of manual labor for repetitive tasks underutilizes resources and is economically inefficient. For these reasons, the food production industry has turned increasingly to technology to eliminate or reduce tasks that are amenable to automation, freeing the human resources for more appropriate tasks.
The production of flat food products presents special challenges. For example, tortillas are generally cooked in a continuous process, wherein the tortillas are transported on a moving conveyor through a conveyor oven, the tortillas being arranged in a number of rows as they pass through the oven. Typically, the tortillas are subsequently accumulated into stacks—for example, 10 to 20 tortillas high (or more)—so that the tortillas can be inserted into bags. Examples of a counting, inspecting, and/or stacking apparatus are disclosed in U.S. Pat. No. 4,530,632, issued to Sela, and U.S. Pat. No. 5,720,593, issued to Pleake, both of which are hereby incorporated by reference. In the apparatus disclosed by Pleake, the tortillas are fed from a conveyor into a trajectory guide and flung through a known flight trajectory to a stacking mechanism. A shaker jostles the stack of tortillas on a movable stack plate, which is lowered to deposit the stack onto a baseplate, wherein a stack removal device moves the stack of tortillas away from the stacking assembly. The stacks of tortillas, disposed in multiple rows or lanes, are transported to a pickup area where they may be manually bagged or moved into a single row on a conveyor for delivery to packaging. Bagging systems are known that will automatically process a single row of stacks of tortillas on a conveyor, automatically inserting the stacks into bags.
The latter manual step is repetitive and inefficient. However, heretofore it has been necessary to accomplish this task by hand for several reasons. First, the stacks of tortillas exit the stacking apparatus in multiple rows or lanes, and in a substantially random order. The irregular ordering is due to irregular placement of the tortillas prior to cooking, inspection, and removal of defective products, and similar factors. Also, typically, the size of the stacks, as well as the diameter of the tortillas, may be adjustable for a given apparatus. It is more difficult to move stacked product in an automated manner due to the tendency of the stacks to tip over (or slidably spread out) due to inertial forces and the like.
Recognizing the need for an apparatus for automatically transferring stacks of tortillas from a multi-row stacker to a single-row conveyor, U.S. Pat. No. 6,454,518, to Garcia-Balleza et al., discloses an apparatus wherein stacks of tortillas are dropped from an upper conveyor onto conveyor blocks disposed on an lower conveyor. Although the disclosed device is an improvement on the art, a disadvantage of the invention taught therein is that the stacks of tortillas may become unstacked due to the abrupt drop onto a moving block. Another disadvantage is that the disclosed system does not appear to be amenable to use with more than one size of tortilla. Garcia-Balleza et al. shows many conventional aspects of suitable conveyor systems, and is therefore also incorporated herein by reference.
Therefore, there remains a need for an apparatus that automatically transfers stacked food product arriving in multiple rows onto a conveyor in a single row.